In the sense of the invention, the term thrust generating devices includes all drive members suitable for the mechanical drive of a watercraft, for example a steerable propeller, a jet drive, a cycloidal propeller and others.
Devices of the foregoing type are already known, for example a control device with a single lever which is supported in two crosswise arranged members which are rotatable about perpendicularly arranged axes, which members operate electrical circuits which control a pair of steerable propellers. If the lever is deflected in any direction which does not lie on an axis of rotation of the members all senders are operated. (See U.S. Pat. No. 3,976,023).
Also, a device of the above-mentioned type is known with which a watercraft can be controlled for rotational and linear movement by means of a lever. The control impulses are forwarded from the lever through sending devices to the thrust generating devices, which serve several functions. They are effective both for linear and also rotational movement of the watercraft. (See German Offenlegungsschrift No. 30 13 654, which corresponds to U.S. Pat. No. 4,418,633).
When two or more functions are combined with a common lever, and a control element thus serves several functions, it is hardly possible to control a change in the direction of travel without necessarily changing the effective thrust strength. If the helmsman wants to carry out only a single control function, he must have great sensitivity and experience in order to do so in a precise manner. In the conventional devices, the effective thrust of the steerable propellers or other thrust generating devices is in some circumstances, for example during forward travel, stronger than that with the same control lever inclination in other circumstances, such as transverse travel. The reason is that, in any desired direction of movement other than straight forward or backward, the thrusts of the steerable propellers are always directed at least partially against one another, namely, at different angles.
It is a purpose of the invention to avoid the described problems, or in other words to provide a device for driving and controlling watercraft and the like with which all conceivable maneuvers and movements can be carried out, for example travel straight ahead and back, rotation along any desired curve and in any desired direction or in one spot, and also transverse movement, if desired with superposed rotation, and in which the required thrust strengths can in each case always be predicted for the helmsman without unintentional changes occurring during adjusting of the presetting lever.
A further very important purpose is to prevent control settings from being inadvertently selected which might endanger the watercraft.
A further purpose of the invention is to make it clear positionally and visibly at the input device, namely, on the lever, handwheel or the like, which direction and thrust strength have been selected for the watercraft. Only through this does an indication for thrust reversal for stopping the vehicle by means of the input device become possible, or at least easier.